I no longer race the 1500m, but when I did, I ran a drill as a workout. It was 3 sets of 3x200m, changing how I ran the last 70m on each rep.
On the last 70m of the first rep of each set, I would consciously increase my cadence by swinging my arms harder and faster, but I would shorten my stride so I would NOT speed up.
On the second rep of each set, over the last 70m I would forcefully push off almost but not quite to the point of bounding. I would try to maintain the same speed... just a strong push off and of course a slower cadence.
On the 3rd rep, I would swing my arms faster to increase cadence AND push off harder. I would fly to the finish. I'd be pretty wiped out, but there was the rest between sets so I could recover.
I do the 2nd and 3rd sets the same way. I wouldn't be too concerned about how fast I ran the 200m because I considered these reps as running drills and not reps per se.
I taught my training partner to do the same workout. That summer we both set 1500m age group records in our state.